A law signed yesterday by Gov. Cuomo requires sex offenders to pose for the camera every 90 days — and whenever they substantially change their appearance — rather than just once a year.

Offenders’ photos are posted on the state’s public sex-offender registry.

Though the law only applies to the highest-risk, or “level 3,” offenders, Cuomo-administration officials said they would subject lower-level sex offenders on parole to the same requirements by administrative rule.

They acknowledged there is no legal penalty for offenders who break the new rules but said those on parole could be sent back to prison.

Cuomo said the law and related measures would “ensure that offenders are carefully tracked with the goal of keeping sex offenders off the street when they pose a risk to society.”